Guys, what if Tony Stark builds Ultron from the tech left behind by the Destroyer from Thor? That way, it ties in more with the entire MCU. As for Winter Soldier, I'm sure whatever will happen there leads directly into the environment where Ultron has to be built, or something along those lines...maybe.

I dunno, either way, I was never a Hank Pym fan, so the fact he's not in the film leaves me ambivalent at best.